示例#1
0
文件: file.go 项目: brgmnn/syncthing
func (s *file) CreateTemp(asc bool) (bt temp, err error) {
	f, err := s.tempFile("", "ql-tmp-")
	if err != nil {
		return nil, err
	}

	fn := f.Name()
	filer := lldb.NewOSFiler(f)
	a, err := lldb.NewAllocator(filer, &lldb.Options{})
	if err != nil {
		f.Close()
		os.Remove(fn)
		return nil, err
	}

	k := 1
	if !asc {
		k = -1
	}

	t, _, err := lldb.CreateBTree(a, func(a, b []byte) int { //TODO w/ error return
		return k * s.collate(a, b)
	})
	if err != nil {
		f.Close()
		if fn != "" {
			os.Remove(fn)
		}
		return nil, err
	}

	x := &fileTemp{file: &file{
		a:     a,
		codec: newGobCoder(),
		f0:    f,
	},
		t: t}
	return x, nil
}
示例#2
0
文件: file.go 项目: brgmnn/syncthing
func newFileFromOSFile(f lldb.OSFile) (fi *file, err error) {
	nm := lockName(f.Name())
	lck, err := lock.Lock(nm)
	if err != nil {
		if lck != nil {
			lck.Close()
		}
		return nil, err
	}

	close := true
	defer func() {
		if close && lck != nil {
			lck.Close()
		}
	}()

	var w *os.File
	closew := false
	wn := walName(f.Name())
	w, err = os.OpenFile(wn, os.O_CREATE|os.O_EXCL|os.O_RDWR, 0666)
	closew = true
	defer func() {
		if w != nil && closew {
			nm := w.Name()
			w.Close()
			os.Remove(nm)
			w = nil
		}
	}()

	if err != nil {
		if !os.IsExist(err) {
			return nil, err
		}

		closew = false
		w, err = os.OpenFile(wn, os.O_RDWR, 0666)
		if err != nil {
			return nil, err
		}

		closew = true
		st, err := w.Stat()
		if err != nil {
			return nil, err
		}

		if st.Size() != 0 {
			return nil, fmt.Errorf("(file-001) non empty WAL file %s exists", wn)
		}
	}

	info, err := f.Stat()
	if err != nil {
		return nil, err
	}

	switch sz := info.Size(); {
	case sz == 0:
		b := make([]byte, 16)
		copy(b, []byte(magic))
		if _, err := f.Write(b); err != nil {
			return nil, err
		}

		filer := lldb.Filer(lldb.NewOSFiler(f))
		filer = lldb.NewInnerFiler(filer, 16)
		if filer, err = lldb.NewACIDFiler(filer, w); err != nil {
			return nil, err
		}

		a, err := lldb.NewAllocator(filer, &lldb.Options{})
		if err != nil {
			return nil, err
		}

		a.Compress = true
		s := &file{
			a:     a,
			codec: newGobCoder(),
			f0:    f,
			f:     filer,
			lck:   lck,
			name:  f.Name(),
			wal:   w,
		}
		if err = s.BeginTransaction(); err != nil {
			return nil, err
		}

		h, err := s.Create()
		if err != nil {
			return nil, err
		}

		if h != 1 { // root
			panic("internal error 043")
		}

		if h, err = s.a.Alloc(make([]byte, 8)); err != nil {
			return nil, err
		}

		if h != 2 { // id
			panic("internal error 044")
		}

		close, closew = false, false
		return s, s.Commit()
	default:
		b := make([]byte, 16)
		if _, err := f.Read(b); err != nil {
			return nil, err
		}

		if string(b[:len(magic)]) != magic {
			return nil, fmt.Errorf("(file-002) unknown file format")
		}

		filer := lldb.Filer(lldb.NewOSFiler(f))
		filer = lldb.NewInnerFiler(filer, 16)
		if filer, err = lldb.NewACIDFiler(filer, w); err != nil {
			return nil, err
		}

		a, err := lldb.NewAllocator(filer, &lldb.Options{})
		if err != nil {
			return nil, err
		}

		bid, err := a.Get(nil, 2) // id
		if err != nil {
			return nil, err
		}

		if len(bid) != 8 {
			return nil, fmt.Errorf("(file-003) corrupted DB: id |% x|", bid)
		}

		id := int64(0)
		for _, v := range bid {
			id = (id << 8) | int64(v)
		}

		a.Compress = true
		s := &file{
			a:     a,
			codec: newGobCoder(),
			f0:    f,
			f:     filer,
			id:    id,
			lck:   lck,
			name:  f.Name(),
			wal:   w,
		}

		close, closew = false, false
		return s, nil
	}
}